From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Graph plotting horsepower against RPM, comparing a water brake test with a dynamometer test at the road wheels.
| Identifier | ExFiles\Box 19\4\ Scan314 | |
| Date | 4th May 1931 guessed | |
| H.P. 100 90 80 70 60 50 40 30 R.P.M. 500 750 1000 1250 1500 1750 2000 2250 2500 2750 3000 UNIT TEST ON HEENAN, FROUDE WATER BRAKE, WITH STANDARD SILENCER WITHOUT CUT-OUT. DYNAMOMETER TEST AT ROAD WHEELS WITH STANDARD EQUIPMENT AS ABOVE. | ||